1. Field of the Invention
The present invention relates to an apparatus and method for controlling a linear voltage regulator.
2. Description of the Related Art
Linear voltage regulators are well known electronic devices. They are used to produce a steady output voltage at a predetermined level from an input voltage which may vary. The input voltage is higher than the output voltage and heat is dissipated in the regulator. The power dissipated given a constant load current is proportional to the voltage drop between the input and the output. For example, in a battery operated system where the operating voltage of the circuitry is significantly lower than the battery voltage, reducing the power dissipation in the regulator will lead to improved battery life. It will also reduce the thermal efficiency requirements of the regulator thereby allowing a small and cheaper package and pass transistor to be used. Conventionally, power supply efficiency has been improved by replacing the pass transistor with a switched inductor. A buck converter uses such an arrangement. However, the inductor tends to be a large and expensive component and is generally not suitable for miniaturization.